The invention relates to a current-supply circuit for feeding an electrical consumer or load, with, the circuit having a switching regulator that is known from background literature. Corresponding circuits are known, for example, from the technical reference book by J. Beckmann, "Getaktete Stromversorgung Clocked Current Supply!," Franzis-Verlag, 1990, pp. 9-34. The switching regulator includes at least one semiconductor power component that is switched completely on or off with a switching signal produced by an actuation circuit. An energy source produces energy with a predetermined output voltage or a predetermined output current through cooperation with inductive and capacitive components. The aforementioned background literature describes current-supply circuits that convert a predetermined input DC voltage into either a smaller or a larger output DC voltage. A DC voltage converter that corresponds to a combination up-down converter is known from the proceedings of the IEEE Power Electronics Specialists Conference in Palo Alto, Calif., Jun. 14-16, 1977. In the known current-supply circuit, the positive terminal of an input DC voltage source is coupled to a first coil. The first coil is connected to a first capacitor. A semiconductor power component alternatingly switches the connecting point between the first coil and the first capacitor, and the connecting point between the first capacitor and a second coil, to a common point between the input DC voltage source and a load. The second coil is in series with the load. A second capacitor is switched in parallel to the load for smoothing. The semiconductor power component can be realized by a transistor connected to the first coil and a diode connected to the second coil, with both the transistor and the diode being switched to the common point between the input DC voltage source and the load.
The output voltage or output current to be predetermined can be varied within specific limits through a corresponding actuation of the at least one semiconductor power component. A large predetermined range is accompanied by the disadvantage that the effectiveness of the current-supply circuit drops in partial ranges. Moreover, the increase in the generation of electromagnetic disturbing radiation, at least in partial ranges, must be taken into account.